private void Search_Click(object sender, RoutedEventArgs e)
{
try
{
BeforeLoadingStockData();
var loadLinesTask = Task.Run(() => {
// This code now runs in a separate thread
var lines = File.ReadAllLines("StockPrices_Small.csv");
return(lines);
});
var processStocksTask = loadLinesTask.ContinueWith(completedTask =>
{
var lines = completedTask.Result;
var data = new List <StockPrice>();
foreach (var line in lines.Skip(1))
{
var price = StockPrice.FromCSV(line);
data.Add(price);
}
// this allows us to pass our code into UI thread for execution
Dispatcher.Invoke(() =>
{
// Warning, do not do here anything heavy or anything that might block the UI thread.
Stocks.ItemsSource = data.Where(sp => sp.Identifier == StockIdentifier.Text);
});
});
processStocksTask.ContinueWith(_ => {
Dispatcher.Invoke(() => {
AfterLoadingStockData();
});
});
}
catch (Exception ex)
{
Notes.Text = ex.Message;
}
finally
{
}
}
private static Task <IEnumerable <StockPrice> > SearchForStocks()
{
var tcs = new TaskCompletionSource <IEnumerable <StockPrice> >();
ThreadPool.QueueUserWorkItem(_ => {
var lines = File.ReadAllLines("StockPrices_Small.csv");
var prices = new List <StockPrice>();
foreach (var line in lines.Skip(1))
{
prices.Add(StockPrice.FromCSV(line));
}
tcs.SetResult(prices); // Communicates the task should be set to completedx.
});
return(tcs.Task);
}
public async IAsyncEnumerable <StockPrice> GetAllStockPrices([EnumeratorCancellation] CancellationToken cancellationToken = default)
{
using var stream = new StreamReader(File.OpenRead("StockPrices_Small.csv"));
await stream.ReadLineAsync(); // Skipping header row
string line;
while ((line = await stream.ReadLineAsync()) != null)
{
if (cancellationToken.IsCancellationRequested)
{
break;
}
yield return(StockPrice.FromCSV(line));
}
}
